<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>盒子的外边距_margin</title>
    <style>
        div {
          width: 400px;
          height: 400px;
          background-color: green;
          /* margin与padding的用法一样 */
          /*margin: 10px;*/

          /*margin-left: 10px;*/
          /*margin-right: 20px;*/
          /*margin-bottom: 40px;*/
          /*margin-top: 30px;*/

          /*margin: 10px 20px;*/
          /*margin: 10px 20px 40px;*/
          margin: 10px 20px 30px 40px;

        }
    </style>
</head>
<body>
    <div></div>
</body>
</html>